Digital Quantum Simulation of Non-Equilibrium Quantum Many-Body Systems*

Digital quantum simulations (DQS) is a driving force behind the development of universal quantum computers. DQS uses the capabilities of quantum computers, such as superposition and entanglement, to determine the dynamics of quantum systems, which are beyond the computability of modern classical computers. A notoriously challenging task in this field is the description of non-equilibrium dynamics in quantum many-body systems, because it defies the methods and principles of equilibrium physics.
Here we use the IBM quantum computers to simulate the non-equilibrium dynamics of few spin and fermionic systems. We explicitly include external perturbations, such as pulsed magnetic fields, to model excitation mechanisms in more realistic situations. Our results reveal, that with a combination of error mitigation, noise extrapolation and optimized initial state preparation, one can tackle the most important drawbacks of modern quantum devices. The systems we simulate demonstrate the potential for large scale quantum simulations of light-matter interactions in the near future.

Benedikt Fauseweh, Jian-Xin Zhu, arXiv:2009.07375 (2020)